Solar Energy

Seeing both sides of light collection

Published

3 years ago

March 17, 2021

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Two types of materials are better than one when it comes to solar cells, as revealed by an international team that has tested a new combination of materials and architecture to improve solar-cell efficiency.

Silicon has long dominated as the premier material for solar cells, helped by its abundance as a raw material. However, perovskites, a class of hybrid organic-inorganic material, are a viable alternative due to their low-cost and large-scale manufacture and potentially higher performance. While still too unstable for full commercialization, they might become available to the market by 2022.

KAUST’s Michele De Bastiani and Stefaan De Wolf, working with colleagues in Canada, Germany and Italy, now show that a combination of the two is the best approach. By optimizing the material composition and the architecture of a “tandem” device, the team has achieved efficiencies beyond commercial silicon solar panels.

Sunlight, of course, comes directly from the sun, but illumination also comes from light reflecting off other surfaces, known as albedo. A device architecture that collects light from the back as well as from the front can utilize this source. “Our bifacial tandems exploit both direct sunlight and the albedo to generate electricity in a more efficient way than their conventional counterparts,” explains De Bastiani.

He and the team started with a simple silicon device structure that was textured top and bottom to enhance light collection. They then used a solution-processing method to deposit a thin perovskite layer on top. A transparent back electrode allowed light in while also allowing a current to flow out. The researchers tested five perovskite materials, each with a different chemical composition, to increase the absorption of incoming light. In this way, they were able to identify the perovskite that best matched the electronic properties of the silicon.

“A restriction of the tandem configuration is the limited current through the lower of the two subcells,” says De Bastiani. “We designed our tandem with a unique feature: the perovskite subcell generates more current than the silicon counterpart by stealing light that would be otherwise absorbed by the bottom subcell.”

The team tested their bifacial devices and compared the performance to similar monofacial devices in various outdoor settings with a range of albedos, such as, for example, bright sandstone or concrete. They found that, in all conditions, the bifacial configuration outperformed the monofacial one.

“We are now investigating the stability of the perovskite while also scaling up the technology to the module level,” says De Bastiani. “For this, we are looking for industrial partners and sponsors.”

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Solar Energy

Chinese astronauts repair space station’s solar wings after debris impact

Published

15 mins ago

April 25, 2024

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Chinese astronauts repair space station’s solar wings after debris impact

by Simon Mansfield

Sydney, Australia (SPX) Apr 25, 2024

The crew of the Shenzhou XVII, stationed on China’s space station, successfully repaired damage to the core module’s solar wings caused by space debris. This repair was accomplished during the country’s inaugural mission involving extravehicular maintenance, according to the China Manned Space Agency.

The astronauts are set to return to Earth on April 30, following the completion of their tasks and the transition of responsibilities to the upcoming Shenzhou XVIII mission.

“The capacity to manage unforeseen challenges in space is a vital aspect of manned space missions,” stated Lin Xiqiang, the deputy director of CMSA, during a press briefing.

Lin explained that the space station’s core module, Tianhe, experienced a reduction in power after debris impacted the solar wing’s power cables. He also noted that the station has conducted several maneuvers to avoid collisions with space debris, a growing concern due to increased human activity in space.

The agency has improved its predictions of the space station and nearby orbital objects’ paths, enhancing its collision avoidance protocols and reducing false alarms by 30%, Lin detailed.

Future plans include using high-definition cameras on the space station’s robotic arm and cameras held by spacewalking astronauts to inspect and assess the external conditions of the station and the potential risks posed by small debris.

The next crew, aboard the Shenzhou XVIII, will focus on enhancing the station’s defenses against space debris by adding protective measures to external piping, cables, and essential systems during their spacewalks.

Additionally, the space station has implemented systems to monitor and pinpoint leaks and developed a pressure emergency response system, significantly extending the time astronauts have to address in-orbit issues.

The China Manned Space Agency continues to update orbital parameters on its website and maintains a safety communication protocol with other major space agencies to share timely information, Lin added.

Based on a Xinhua News Agency article

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Solar Energy

Buck the Duck Curve: California’s Bold Leap Towards Solar Empowerment

Published

2 days ago

April 23, 2024

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Buck the Duck Curve: California’s Bold Leap Towards Solar Empowerment

by Bradley Bartz, President/Founder, ABC Solar

Los Angeles CA (SPX) Apr 23, 2024

In the sun-drenched state of California, solar power has been both a beacon of hope and a point of contention. At the heart of this debate lies the infamous “Solar Duck Curve”-a phenomenon critics have used to demonize the impact of solar power on the energy grid. This curve, which charts the mismatch between peak solar production and peak demand, has been portrayed as a nightmare for grid management. However, much like the visionary approach of Hong Kong’s free phone service in the past, California has the potential to transform this perceived problem into a profitable solution.

The Buck Load Initiative: A Call to Action

Governor Gavin Newsom has a golden opportunity to rewrite the narrative. Just as Hong Kong revolutionized communication by offering free phone service, making long distance calls economically accessible and turning a high-cost luxury into a distributed wealth generator, California can harness the currently curtailed solar power to fuel new economic frontiers.

Today, the reality is that the production of solar energy often exceeds demand during daylight hours, leading to what is known as ‘curtailment’. This means valuable, clean energy-energy that could power homes, businesses, and innovative technologies-is wasted. It’s akin to collecting rainwater in a drought-stricken land but pouring it down the drain just when it’s needed most.

Why The Buck Load?

The Buck Load is more than just a concept; it’s a directive for progress. This initiative proposes using surplus solar energy to power high-demand facilities and projects, such as high-speed wind tunnels for wildfire research or new industrial complexes, creating jobs and fostering innovation. It’s a win-win scenario where excess energy meets peak ingenuity, fostering a robust, sustainable economy.

Imagine this: instead of shutting down solar panels, we channel excess energy into research facilities, manufacturing plants, and even cryptocurrency mining operations-anywhere that can use high amounts of electricity outside of peak hours. We could turn every ray of sunshine into a thread in the fabric of a new economic miracle.

A Vision for the Future

As the President and Founder of ABC Solar, I’ve seen firsthand the capabilities and the limitations of our current energy practices. It’s time for a bold step forward. The Buck Load isn’t just about energy; it’s about setting a precedent for how we value and utilize our natural resources. It’s about ensuring that every Californian has the power they need, not just to survive, but to thrive.

Governor Newsom, the California Public Utilities Commission, and all stakeholders in our energy future are at a crossroads. We can continue down a path of restrictions and limitations, or we can choose a path of innovation and abundance. The Buck Load is the key to unlocking a future where California continues to lead the world in environmental consciousness and economic innovation.

Let us not be the Mr. Burns of our own narrative, shading the world from the potential of solar power. Let’s be the pioneers who used the sun to light up not just our homes, but our economy. Let’s make The Buck Load initiative a reality and show the world what California can do.

The time is now. Let’s not wait for tomorrow to solve the problems we can solve today. Let’s harness the full potential of the sun, and in doing so, fund our future-a future as bright as the California sun.

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Solar Energy

Efficient DC power converter enhances microgrid sustainability

Published

2 days ago

April 23, 2024

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Efficient DC power converter enhances microgrid sustainability

by Riko Seibo

Tokyo, Japan (SPX) Apr 22, 2024

A novel DC-DC power converter developed by Kobe University promises enhanced energy storage and conversion efficiency, marking a key step in advancing microgrid technologies. This new converter, designed to integrate seamlessly with various DC energy sources, improves system stability and simplicity with an unprecedented operational efficiency.

Electric power is classified into two types: AC (alternating current) and DC (direct current). Despite AC being the chosen standard for national power grids, the reliance on DC power by solar panels, batteries, electric vehicles, and computers necessitates a conversion, often with significant energy loss. The adoption of DC microgrids could mitigate this by directly linking renewable energy sources and storage units to consumers, eliminating the need for conversion and allowing for voltage flexibility essential for diverse applications.

Researchers from Kobe University and National Chung Hsing University, including MISHIMA Tomokazu and LAI Ching-Ming, have spearheaded the development of this technology. “Our interdisciplinary approach and advanced facilities have underpinned our success in developing a prototype that demonstrates significant advantages over existing systems,” explained LIU Shiqiang, a student team member at Kobe University.

The new design, featured in the journal IEEE Transactions on Power Electronics, optimizes voltage ratio and inductor current balance, improving performance for electric vehicle-centric applications. “The asymmetrical duty limit control is particularly beneficial for electric vehicle-connected DC microgrids,” Liu added.

The prototype’s effectiveness, showing efficiencies up to 98.3%, underscores its potential for real-world application and sets the stage for further enhancements and commercialization efforts by UPE-Japan, a startup emerging from Kobe University. “Our aim is to foster the shift towards more reliable and sustainable energy solutions, especially for electric vehicles and renewable energy systems,” Liu stated.

Research Report:Over 98% Efficiency SiC-MOSFET based Four-Phase Interleaved Bidirectional DC-DC Converter Featuring Wide-Range Voltage Ratio